Add missing unit tests for PR #5499 (#5527)

Part of #5410

browser/app/js/browser/__tests__/SideBar.test.js

@@ -23,5 +23,10 @@ describe("SideBar", () => {
     shallow(<SideBar />)
   })
 
-  // ClickOutHandler test to be added when corresponding function is added
+  it("should call clickOutside when the user clicks outside the sidebar", () => {
+    const clickOutside = jest.fn()
+    const wrapper = shallow(<SideBar clickOutside={clickOutside} />)
+    wrapper.simulate("clickOut", { preventDefault: jest.fn() })
+    expect(clickOutside).toHaveBeenCalled()
+  })
 })